Food service furniture, such as tables and countertops, must possess certain characteristics for acceptable use. One such characteristic is cleanability. Exposure to cleaning agents, abrasives, cutting utensils and the like over a number of years can badly damage most materials used for countertops, table tops, vanity tops and the like. At present, commercial and residential food service furniture is constructed of metal (i.e., stainless steel), plastic laminates (i.e., Formica), marble, wood, mineral-filled resins and the like. The use of laminates and wood for food service furniture has been accepted for years, however, it is subject to deterioration (i.e., scratching and burning) and, as an eating surface, it is difficult to clean due to its porous character. Metal surfaces have been used in the past, however, they are expensive, require significant maintenance and are not favored in residential kitchen and bathroom settings.
One surface material that has recently gained favor is the solid surface or cultured marble material. The term "solid surface" pertains to a material where there is no painted or laminated skin or outer surface. With solid surface materials, small scratches, burns and the like are simply sanded or buffed out.
The industry for solid surfacing began about 25 years ago when duPont, Inc. developed a high quality surface material known commercially as Corian.RTM.. Since the early 1980's, several major manufacturers have developed their own brand of solid surface products. For the most part, these products are expensive to produce and are utilized by cutting a sheet of the SSM into the desired shape and then grinding edges and/or bonding other features through the use of an adhesive. A major cost associated with solid surface materials is that for horizontal applications (i.e., table tops, vanity top, kitchen countertops), the manufacturers recommend, and will only guarantee, thickness of 1/2 inch or greater. The manufacturers have determined that for horizontal applications, thicknesses of less than 1/2 inch are subject to cracking and compression failure even when applied to a substrate such as wood or particle board. Further, solid surface materials do not adhere to substrates such as steel or aluminum and thus separation of the composite results in cracking or impact damage. The industry has attempted to reduce the costs of SSM horizontal surfaces through reducing the thickness of the solid surface material without success. Bonding of solid surface materials with a thickness of less than 1/2 inch to conventional substrates has failed to convince the solid surface manufacturers that warranties, expected by the consumer, can be granted.
In its most general aspect, the present invention uses a fiber reinforced concrete (FRC) and a bonding feature to address the shortcomings of the prior art substrate materials for solid surface materials. The solid surface material (SSM) is highly desirable as it provides a surface that is non-porous, resistant to staining, easily cleaned and resistant to environmental degradation. The FRC provides the required mass, impact resistance, structural strength and a low cost of production. An additional aspect of the invention relates to a process for manufacturing the composite wherein the interior surface (surface in contact with the concrete substrate) of the SSM comprises a bonding feature to assure proper bonding of the SSM to the concrete substrate. While the use of wooden substrates for SSM is known, the countertop, vanity and table industries have failed to appreciate the numerous advantages that FRC/SSM composites can bring to food service and bathroom furniture. One possible reason for overlooking the FRC/SSM composite is the lack of adhesion between such dissimilar materials. One aspect of this invention is the discovery that certain structural features of the inventive composite will overcome this adhesion problem. A further aspect of the invention relates to methods of producing such FRC/SSM composites.